Abstract

Post-mixed waterjet peening is an effective treatment method for compressive residual stress field. After peening, the surface quality of the parts is low, and the hardness is usually higher than 60HRC. A fine manufacturing process should be carried out to obtain a satisfactory surface roughness without side effect on existing residual stress. In this article, the 18CrNiMo7-6 steel after carburization was subjected to post-mixed waterjet peening, the surface hardness was 66HRC and the maximum compressive residual stress was about 1242.86 MPa. Hard milling with CBN inserts were used to remove the rough surface layer of 18CrNiMo7-6. The hardness after milling has changed about 1-2HRC lower than that before cutting. When the cutting speed v_c is 753.6 m/min, the feed speed v_f is 0.04 mm/min and the cutting depth a_p is 0.02 mm, compared to the original Ra 1.204 μm, the best surface roughness can reach Ra 0.0823 μm. When a_p exceeds the maximum residual stress location point of 60 μm, the cutting effect will significantly change the residual stress. Considering the hardness, surface roughness and residual stress, the recommended milling parameters v_f and a_p should use the lower values, the range of v_c should be 500–700 m/min and sufficient coolant is required during the cutting process.

抽象的

后混合喷水喷丸是一种有效的处理残余压应力场的方法。喷丸后，零件的表面质量较低，硬度通常高于60HRC。应该进行精细的制造工艺以获得令人满意的表面粗糙度，而又不会对现有残余应力产生副作用。本文对渗碳后的18CrNiMo7-6钢进行了后混合水射流喷丸处理，表面硬度为66HRC，最大压缩残余应力约为1242.86 MPa。使用带有CBN刀片的硬铣削来去除18CrNiMo7-6的粗糙表面层。铣削后的硬度比切削前降低了约1-2HRC。切削速度v _c为753.6 m / min时，进给速度v _f为0.04 mm / min，切削深度a _p为0.02 mm，与原始Ra 1.204μm相比，最佳表面粗糙度可以达到Ra 0.0823μm。当一个_p超过60微米的最大残留应力的位置点，切割效果将显著改变残余应力。考虑到硬度，表面粗糙度和残余应力，建议的铣削参数v _f和a _p应使用较低的值，v _c的范围应为500–700 m / min，并且在切削过程中需要足够的冷却液。